private void ConstructPortals()
{
PortalCells = new Dictionary <GridPoint, string>();
Portals = new Dictionary <string, IList <GridPoint> >();
var emptyCells = MazeCells
.Where(kvp => DonutMazeCellType.Empty.Equals(kvp.Value.Type));
foreach (var emptyCell in emptyCells)
{
var point = emptyCell.Key;
var movementDirections = new List <MovementDirection>()
{
MovementDirection.Down,
MovementDirection.Left,
MovementDirection.Right,
MovementDirection.Up
};
foreach (var direction in movementDirections)
{
// Assumption: One point can only be associated with at
// most one portal.
var neighbor1 = point.Move(direction, 1);
if (!MazeCells.ContainsKey(neighbor1) ||
!DonutMazeCellType.Portal.Equals(MazeCells[neighbor1].Type))
{
continue;
}
var neighbor2 = point.Move(direction, 2);
if (!MazeCells.ContainsKey(neighbor2) ||
!DonutMazeCellType.Portal.Equals(MazeCells[neighbor2].Type))
{
throw new Exception("Only one neighboring portal cell found");
}
var portalId = string.Empty;
if (MovementDirection.Right.Equals(direction) ||
MovementDirection.Up.Equals(direction))
{
portalId = MazeCells[neighbor1].PortalLetter + MazeCells[neighbor2].PortalLetter;
}
else
{
portalId = MazeCells[neighbor2].PortalLetter + MazeCells[neighbor1].PortalLetter;
}
PortalCells.Add(point, portalId);
if (!Portals.ContainsKey(portalId))
{
Portals.Add(portalId, new List <GridPoint>());
}
Portals[portalId].Add(point);
}
}
EntrancePoint = new GridPoint3D(Portals[EntrancePortalId][0], 0);
ExitPoint = new GridPoint3D(Portals[ExitPortalId][0], 0);
}
private void CalculateMazeBoundaries()
{
OuterWallLeft = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type))
.Min(kvp => kvp.Key.X);
OuterWallRight = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type))
.Max(kvp => kvp.Key.X);
OuterWallTop = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type))
.Min(kvp => kvp.Key.Y);
OuterWallBottom = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type))
.Max(kvp => kvp.Key.Y);
int midX = (OuterWallRight - OuterWallLeft) / 2;
int midY = (OuterWallBottom - OuterWallTop) / 2;
InnerWallLeft = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type) &&
kvp.Key.X <= midX &&
kvp.Key.Y == midY)
.Max(kvp => kvp.Key.X);
InnerWallRight = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type) &&
kvp.Key.X >= midX &&
kvp.Key.Y == midY)
.Min(kvp => kvp.Key.X);
InnerWallTop = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type) &&
kvp.Key.Y <= midY &&
kvp.Key.X == midX)
.Max(kvp => kvp.Key.Y);
InnerWallBottom = MazeCells
.Where(kvp => !DonutMazeCellType.Portal.Equals(kvp.Value.Type) &&
kvp.Key.Y >= midY &&
kvp.Key.X == midX)
.Min(kvp => kvp.Key.Y);
}